1. FIELD OF THE INVENTION
The present invention is related generally to hand tools, and more specifically to a disposable spray shield for use by painters and the like to prevent overspray onto areas adjacent surfaces being sprayed.
2. DESCRIPTION OF THE PRIOR ART
Spray guns and aerosols of various kinds are very practical devices for applying paints, adhesives, architectural texturing materials, and the like to surfaces. Spray applications of such materials are much faster and more economical than conventional hand application techniques, and, in some spraying provides a more pleasing or desired functional or visual effect of the sprayed material. However, a pervasive problem in the use of such spray techniques is that a spray pattern by its nature, is not precise. While the main spray pattern is directed at the area to be sprayed, some of the material around the periphery of the pattern drifts or mists over a wider area. Such mist or particles or droplets of the sprayed material around the periphery of the targeted area is known as "overspray." Thus, when the surface to be sprayed is adjacent an area or surface not to be sprayed, it is necessary to mask or shield such area or surface not to be sprayed from the material overspray.
One conventional method of protecting adjacent surfaces from such overspray is to mask the area to be protected with a covering or adhesive tape or the like. Such masking is effective, but it is very time-consuming. Also, there are situations, such as where carpet meets a baseboard to be sprayed, where effective masking is very difficult, if not impossible.
Another conventional technique, more significant to this invention, is the use of a large portable shield that can be positioned at the edge of the surface to be sprayed in order to cover or protect the adjacent surface that is not to be sprayed. There are available hand-held portable shields for such use. Such hand-held shields in use such as spray painting or applying texturing materials to walls and ceilings, have to have a significantly large surface area, usually in the range of three or more square feet, in order to effectively prevent overspray from spray guns. To be effective and useable, such shields have to be light-weight, so they can be held in one hand by the user, sometimes in awkward or outstretched arm positions. Yet, they must be structurally rigid to maintain a planar shape and a straight leading or "cutting" edge for defining a sharp, straight line or edge at the border of the surface being sprayed. In order to provide sufficient structural rigidity to such a large surface area, yet to maintain the necessary thinness, light-weight and maneuverability requirements, such spray paint shields are conventionally fabricated with a flat, thin metallic sheet such as steel or aluminum alloy with a handle attached thereto for gripping and manipulating the shield. While such conventional metallic shield devices do perform the shielding function for which they are intended, there are a number of problems associated with their use that have not heretofore been solved. First, they are still heavier and more tedious to hold over extended periods of time than desirable. Second, the materials being sprayed, such as paints, glues, and texturing materials, have some adhesive characteristics. Therefore, use of the shield over an extended period of time will result in a substantial build-up of the sprayed material on the exposed surface of the shield. The build-up of such material becomes very heavy and unwieldy for a person to handle. It also distorts the leading edge of the shield and affects the ability of the user to "cut" or define a clear sharp edge or line at the border of the surface being sprayed. Depending to some extent on the adhesive characteristics of the materials being used, it is often difficult and very time-consuming to clean such materials from the shield surface. On the other hand, such conventional metal shields are too expensive to discard them or replace them with new shields. Therefore, as usually happens, a worker spends much more time than should be necessary trying to use a shield that has too much heavy spray material built up on the surface thereof, yet being reluctant to discard the shield and to replace it with a new one. They also spend more time than is economical trying to clean the surfaces of such shields. Further, if the leading or cutting edge of the shield becomes nicked or distorted or deformed in some manner, the accuracy of the edge or line to be cut at the edge of the surface to be sprayed is distorted and becomes undesirable for most uses. Unfortunately, such bending or distortions occur quite frequently in normal use. Therefore, many expensive metal shields with damaged edges or uncleanable build-up on the surfaces have to be discarded, in spite of the expense of purchasing new ones.
As a substitute for the expensive commercial metal shields, some painters or workers attempt to use less expensive materials, such as sheets of cardboard or plastic, for paint shields. However, such materials do not usually have sufficient structural rigidity or strength to maintain a planar shape and a straight leading edge as required for effective spray shields in most applications. They also are not conducive to holding and handling over extended periods of time. Such substitutions are usually not very satisfactory.
Consequently, while the more expensive metal spray shields available are effective when they are new, they lose their effectiveness as material builds on the surface and as the leading edges become damaged or deformed through normal use, yet they are too expensive to throw away. On the other hand, prior attempts to use cheaper materials have not been satisfactory because they are not sufficiently rigid and they do not provide adequate means for holding and manipulating them.